1. Field of the Invention
The present invention relates generally to software and hardware test, logic array and hybrid testers, test architecture, test coverage and, in particular, to test generation tools, test coverage and system level testing.
2. Description of Related Art
One of the challenging issues in random testing is measuring the test coverage of a given test generation tool. In conventional pseudo-random test generation methods, test cases are built by using streams of instructions and/or input/output commands selected from a group containing instructions and/or commands. Depending on the system under test (SUT), the number of valid instructions can be on the order of hundreds or even thousands. The selection criteria for these instructions has a direct impact on the achieved test coverage. The complexity of measuring the test coverage increases with the complexity of the SUT. Introducing a new test coverage measurement mechanism into an existing test generation tool can be time consuming and difficult.
Estimating and improving test case generation is important for gaining confidence in system tests and to improve test quality. Measuring test coverage of a given test generation tool can be costly. Tracking each instruction and using feedback (between the test case build and result prediction processes) requires extensive analysis and consumes substantial test time.
There is a need for a test coverage measuring and enhancing method that can be easily incorporated into existing pseudo-random test generation methods. Also, there is a need for a method that includes biasing schemes used by pseudo-random test case generation methods.